This example shows a smiley face drawn with React and D3, rendered as SVG inside a single component. The smiley is centered and composed of three circles—a yellow face with a black stroke, plus two eyes—and a mouth arc. The code mixes React elements for the circles with a D3 `arc()` generator to define the mouth’s path, using fixed values for position and radius. The face is constructed without external data, and the entire graphic is produced declaratively within `ReactDOM.render`.